Merge pull request #2459 from SixLabors/bp/Issue2456

JimBobSquarePants · web-flow · commit b9e3cd8b26fa · 2023-05-19T08:44:49.000+10:00
Tiff: Undo horizontal predictor for cmyk images
diff --git a/src/ImageSharp/Formats/Tiff/Compression/HorizontalPredictor.cs b/src/ImageSharp/Formats/Tiff/Compression/HorizontalPredictor.cs
@@ -44,6 +44,7 @@ public static void Undo(Span<byte> pixelBytes, int width, TiffColorType colorTyp
                 UndoRgb24Bit(pixelBytes, width);
                 break;
             case TiffColorType.Rgba8888:
+            case TiffColorType.Cmyk:
                 UndoRgba32Bit(pixelBytes, width);
                 break;
             case TiffColorType.Rgb161616:
diff --git a/tests/ImageSharp.Tests/Formats/Tiff/TiffDecoderTests.cs b/tests/ImageSharp.Tests/Formats/Tiff/TiffDecoderTests.cs
@@ -308,6 +308,7 @@ public void TiffDecoder_CanDecode_CieLab<TPixel>(TestImageProvider<TPixel> provi
 
     [Theory]
     [WithFile(Cmyk, PixelTypes.Rgba32)]
+    [WithFile(CmykLzwPredictor, PixelTypes.Rgba32)]
     public void TiffDecoder_CanDecode_Cmyk<TPixel>(TestImageProvider<TPixel> provider)
         where TPixel : unmanaged, IPixel<TPixel>
     {
diff --git a/tests/ImageSharp.Tests/TestImages.cs b/tests/ImageSharp.Tests/TestImages.cs
@@ -958,6 +958,7 @@ public static class Tiff
 
         public const string Cmyk = "Tiff/Cmyk.tiff";
         public const string Cmyk64BitDeflate = "Tiff/cmyk_deflate_64bit.tiff";
+        public const string CmykLzwPredictor = "Tiff/Cmyk-lzw-predictor.tiff";
 
         public const string Issues1716Rgb161616BitLittleEndian = "Tiff/Issues/Issue1716.tiff";
         public const string Issues1891 = "Tiff/Issues/Issue1891.tiff";
diff --git a/tests/Images/External/ReferenceOutput/TiffDecoderTests/TiffDecoder_CanDecode_Cmyk_Rgba32_Cmyk-lzw-predictor.png b/tests/Images/External/ReferenceOutput/TiffDecoderTests/TiffDecoder_CanDecode_Cmyk_Rgba32_Cmyk-lzw-predictor.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:db076491d7afc78cb5de99cb1e7a9c53f891157bf064994c60d453aec75b9c90
+size 512
diff --git a/tests/Images/Input/Tiff/Cmyk-lzw-predictor.tiff b/tests/Images/Input/Tiff/Cmyk-lzw-predictor.tiff
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d322e42dd61c528e91ba9d16310248a4b9a77094a22761dcb9e6f132fc16fe1b
+size 1080

Original file line number	Diff line number	Diff line change
`@@ -308,6 +308,7 @@ public void TiffDecoder_CanDecode_CieLab<TPixel>(TestImageProvider<TPixel> provi`
`308`	`308`
`309`	`309`	`[Theory]`
`310`	`310`	`[WithFile(Cmyk, PixelTypes.Rgba32)]`
	`311`	`+ [WithFile(CmykLzwPredictor, PixelTypes.Rgba32)]`
`311`	`312`	`public void TiffDecoder_CanDecode_Cmyk<TPixel>(TestImageProvider<TPixel> provider)`
`312`	`313`	`where TPixel : unmanaged, IPixel<TPixel>`
`313`	`314`	`{`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+version https://git-lfs.github.com/spec/v1`
	`2`	`+oid sha256:d322e42dd61c528e91ba9d16310248a4b9a77094a22761dcb9e6f132fc16fe1b`
	`3`	`+size 1080`